In an isotonic environment, the relative concentrations of solute and water are equal on both sides of the membrane. ... If placed in a hypotonic solution, a red blood cell will bloat up and may explode, while in a hypertonic solution, it will shrivel—making the cytoplasm dense and its contents concentrated—and may die.
If a cell is placed in a hypertonic solution, water will leave the cell, and the cell will shrink. In an isotonic environment, the relative concentrations of solute and water are equal on both sides of the membrane. ... When a cell is placed in a hypotonic environment, water will enter the cell, and the cell will swell.